IF(NOT EXISTS(SELECT * FROM syscolumns WHERE name = 'id' AND OBJECT_NAME(id) = 'feriados'))
BEGIN
	DECLARE @PKName AS VARCHAR(50)

	SELECT @PKName = name
	FROM sysobjects
	WHERE OBJECT_NAME(parent_obj) = 'feriados' AND xtype = 'PK'

	EXEC('ALTER TABLE feriados
	DROP CONSTRAINT ' + @PKName)

	ALTER TABLE feriados
	ADD id int IDENTITY(1,1) PRIMARY KEY
END